Ctenodrilus cf. serratus (Schmidt 1857)
Simple body plan, few obvious distinguishing characters. Small, 1.5 – 2.2 mm long. Body translucent, skin with black-brown spots, reddish-brown intestine visible. Nuchal organs large ciliated pits lateral on prostomium, visible as unpigmented patches on live worms. Noto- and neurochaetae identical, slightly bent and broadened distally, 4 – 7 teeth.
Intertidal, sediment (often in aquaria). In South Africa on oysters from on-shore pond culture.
South Africa: Northern Cape coast
English Channel, North Sea (Type locality France), Mediterranean, Japan, New Zealand, Caribbean, Baja California.
Amphi-Atlantic distribution confirmed. Too few individuals found in SA to confirm identity.